How would you go about changing the bearings.I have a /06 Ram1500 5.7L Hemi. Guess there are two(front & rear). With the whining noise I'm not sure which one to change without going to the expense of a garage.Guess the alt would have to come off.

 

Easiest way is... http://www.rockauto.com/catalog/moreinfo.php?pk=3375009

Just get a new alternator, 15 minute fix.

 

Agreed. Why would you bother?

 

I agree,but i think that its the idler pulley.the dodge dealership here says that they after changing a few.i just have to wait until next week when their mechanic gets back.will it destroy the belt if it does go?

 

The idller pulley is an easy DIY, I would get a new belt is it looks cracked or worn. There is a mark on the pulley indicating it has moved too far. Download the 06 service manual from the DIY section and look into it.

 

If its the stationary idler pulley you loosen one bolt, install the new part (about $10) and your done. If its the tensioner pulley, it's the same process. The bolt may be reverse threaded on one of them though, I can't remember.
If the pulley bearings fall apart the pulley will wobble or even fall off and both cases will damage the belt.